include/net/ip_tunnels.h

   1 #ifndef __NET_IP_TUNNELS_H
   2 #define __NET_IP_TUNNELS_H 1
   3
   4 #include <linux/if_tunnel.h>
   5 #include <linux/netdevice.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/socket.h>
   8 #include <linux/types.h>
   9 #include <linux/u64_stats_sync.h>
  10 #include <linux/bitops.h>
  11
  12 #include <net/dsfield.h>
  13 #include <net/gro_cells.h>
  14 #include <net/inet_ecn.h>
  15 #include <net/netns/generic.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/lwtunnel.h>
  18 #include <net/dst_cache.h>
  19
  20 #if IS_ENABLED(CONFIG_IPV6)
  21 #include <net/ipv6.h>
  22 #include <net/ip6_fib.h>
  23 #include <net/ip6_route.h>
  24 #endif
  25
  26 /* Keep error state on tunnel for 30 sec */
  27 #define IPTUNNEL_ERR_TIMEO      (30*HZ)
  28
  29 /* Used to memset ip_tunnel padding. */
  30 #define IP_TUNNEL_KEY_SIZE      offsetofend(struct ip_tunnel_key, tp_dst)
  31
  32 /* Used to memset ipv4 address padding. */
  33 #define IP_TUNNEL_KEY_IPV4_PAD  offsetofend(struct ip_tunnel_key, u.ipv4.dst)
  34 #define IP_TUNNEL_KEY_IPV4_PAD_LEN                              \
  35         (FIELD_SIZEOF(struct ip_tunnel_key, u) -                \
  36          FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
  37
  38 struct ip_tunnel_key {
  39         __be64                  tun_id;
  40         union {
  41                 struct {
  42                         __be32  src;
  43                         __be32  dst;
  44                 } ipv4;
  45                 struct {
  46                         struct in6_addr src;
  47                         struct in6_addr dst;
  48                 } ipv6;
  49         } u;
  50         __be16                  tun_flags;
  51         u8                      tos;            /* TOS for IPv4, TC for IPv6 */
  52         u8                      ttl;            /* TTL for IPv4, HL for IPv6 */
  53         __be32                  label;          /* Flow Label for IPv6 */
  54         __be16                  tp_src;
  55         __be16                  tp_dst;
  56 };
  57
  58 /* Flags for ip_tunnel_info mode. */
  59 #define IP_TUNNEL_INFO_TX       0x01    /* represents tx tunnel parameters */
  60 #define IP_TUNNEL_INFO_IPV6     0x02    /* key contains IPv6 addresses */
  61 #define IP_TUNNEL_INFO_BRIDGE   0x04    /* represents a bridged tunnel id */
  62
  63 /* Maximum tunnel options length. */
  64 #define IP_TUNNEL_OPTS_MAX                                      \
  65         GENMASK((FIELD_SIZEOF(struct ip_tunnel_info,            \
  66                               options_len) * BITS_PER_BYTE) - 1, 0)
  67
  68 struct ip_tunnel_info {
  69         struct ip_tunnel_key    key;
  70 #ifdef CONFIG_DST_CACHE
  71         struct dst_cache        dst_cache;
  72 #endif
  73         u8                      options_len;
  74         u8                      mode;
  75 };
  76
  77 /* 6rd prefix/relay information */
  78 #ifdef CONFIG_IPV6_SIT_6RD
  79 struct ip_tunnel_6rd_parm {
  80         struct in6_addr         prefix;
  81         __be32                  relay_prefix;
  82         u16                     prefixlen;
  83         u16                     relay_prefixlen;
  84 };
  85 #endif
  86
  87 struct ip_tunnel_encap {
  88         u16                     type;
  89         u16                     flags;
  90         __be16                  sport;
  91         __be16                  dport;
  92 };
  93
  94 struct ip_tunnel_prl_entry {
  95         struct ip_tunnel_prl_entry __rcu *next;
  96         __be32                          addr;
  97         u16                             flags;
  98         struct rcu_head                 rcu_head;
  99 };
 100
 101 struct metadata_dst;
 102
 103 struct ip_tunnel {
 104         struct ip_tunnel __rcu  *next;
 105         struct hlist_node hash_node;
 106         struct net_device       *dev;
 107         struct net              *net;   /* netns for packet i/o */
 108
 109         unsigned long   err_time;       /* Time when the last ICMP error
 110                                          * arrived */
 111         int             err_count;      /* Number of arrived ICMP errors */
 112
 113         /* These four fields used only by GRE */
 114         u32             i_seqno;        /* The last seen seqno  */
 115         u32             o_seqno;        /* The last output seqno */
 116         int             tun_hlen;       /* Precalculated header length */
 117
 118         /* This field used only by ERSPAN */
 119         u32             index;          /* ERSPAN type II index */
 120
 121         struct dst_cache dst_cache;
 122
 123         struct ip_tunnel_parm parms;
 124
 125         int             mlink;
 126         int             encap_hlen;     /* Encap header length (FOU,GUE) */
 127         int             hlen;           /* tun_hlen + encap_hlen */
 128         struct ip_tunnel_encap encap;
 129
 130         /* for SIT */
 131 #ifdef CONFIG_IPV6_SIT_6RD
 132         struct ip_tunnel_6rd_parm ip6rd;
 133 #endif
 134         struct ip_tunnel_prl_entry __rcu *prl;  /* potential router list */
 135         unsigned int            prl_count;      /* # of entries in PRL */
 136         unsigned int            ip_tnl_net_id;
 137         struct gro_cells        gro_cells;
 138         __u32                   fwmark;
 139         bool                    collect_md;
 140         bool                    ignore_df;
 141 };
 142
 143 #define TUNNEL_CSUM             __cpu_to_be16(0x01)
 144 #define TUNNEL_ROUTING          __cpu_to_be16(0x02)
 145 #define TUNNEL_KEY              __cpu_to_be16(0x04)
 146 #define TUNNEL_SEQ              __cpu_to_be16(0x08)
 147 #define TUNNEL_STRICT           __cpu_to_be16(0x10)
 148 #define TUNNEL_REC              __cpu_to_be16(0x20)
 149 #define TUNNEL_VERSION          __cpu_to_be16(0x40)
 150 #define TUNNEL_NO_KEY           __cpu_to_be16(0x80)
 151 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
 152 #define TUNNEL_OAM              __cpu_to_be16(0x0200)
 153 #define TUNNEL_CRIT_OPT         __cpu_to_be16(0x0400)
 154 #define TUNNEL_GENEVE_OPT       __cpu_to_be16(0x0800)
 155 #define TUNNEL_VXLAN_OPT        __cpu_to_be16(0x1000)
 156 #define TUNNEL_NOCACHE          __cpu_to_be16(0x2000)
 157 #define TUNNEL_ERSPAN_OPT       __cpu_to_be16(0x4000)
 158
 159 #define TUNNEL_OPTIONS_PRESENT \
 160                 (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)
 161
 162 struct tnl_ptk_info {
 163         __be16 flags;
 164         __be16 proto;
 165         __be32 key;
 166         __be32 seq;
 167         int hdr_len;
 168 };
 169
 170 #define PACKET_RCVD     0
 171 #define PACKET_REJECT   1
 172 #define PACKET_NEXT     2
 173
 174 #define IP_TNL_HASH_BITS   7
 175 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
 176
 177 struct ip_tunnel_net {
 178         struct net_device *fb_tunnel_dev;
 179         struct hlist_head tunnels[IP_TNL_HASH_SIZE];
 180         struct ip_tunnel __rcu *collect_md_tun;
 181 };
 182
 183 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
 184                                       __be32 saddr, __be32 daddr,
 185                                       u8 tos, u8 ttl, __be32 label,
 186                                       __be16 tp_src, __be16 tp_dst,
 187                                       __be64 tun_id, __be16 tun_flags)
 188 {
 189         key->tun_id = tun_id;
 190         key->u.ipv4.src = saddr;
 191         key->u.ipv4.dst = daddr;
 192         memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
 193                0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
 194         key->tos = tos;
 195         key->ttl = ttl;
 196         key->label = label;
 197         key->tun_flags = tun_flags;
 198
 199         /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
 200          * the upper tunnel are used.
 201          * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
 202          */
 203         key->tp_src = tp_src;
 204         key->tp_dst = tp_dst;
 205
 206         /* Clear struct padding. */
 207         if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
 208                 memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
 209                        0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
 210 }
 211
 212 static inline bool
 213 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
 214                            const struct ip_tunnel_info *info)
 215 {
 216         if (skb->mark)
 217                 return false;
 218         if (!info)
 219                 return true;
 220         if (info->key.tun_flags & TUNNEL_NOCACHE)
 221                 return false;
 222
 223         return true;
 224 }
 225
 226 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
 227                                                *tun_info)
 228 {
 229         return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 230 }
 231
 232 static inline __be64 key32_to_tunnel_id(__be32 key)
 233 {
 234 #ifdef __BIG_ENDIAN
 235         return (__force __be64)key;
 236 #else
 237         return (__force __be64)((__force u64)key << 32);
 238 #endif
 239 }
 240
 241 /* Returns the least-significant 32 bits of a __be64. */
 242 static inline __be32 tunnel_id_to_key32(__be64 tun_id)
 243 {
 244 #ifdef __BIG_ENDIAN
 245         return (__force __be32)tun_id;
 246 #else
 247         return (__force __be32)((__force u64)tun_id >> 32);
 248 #endif
 249 }
 250
 251 #ifdef CONFIG_INET
 252
 253 int ip_tunnel_init(struct net_device *dev);
 254 void ip_tunnel_uninit(struct net_device *dev);
 255 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 256 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 257 int ip_tunnel_get_iflink(const struct net_device *dev);
 258 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
 259                        struct rtnl_link_ops *ops, char *devname);
 260
 261 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
 262
 263 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 264                     const struct iphdr *tnl_params, const u8 protocol);
 265 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 266                        const u8 proto);
 267 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 268 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 269 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 270
 271 void ip_tunnel_get_stats64(struct net_device *dev,
 272                            struct rtnl_link_stats64 *tot);
 273 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 274                                    int link, __be16 flags,
 275                                    __be32 remote, __be32 local,
 276                                    __be32 key);
 277
 278 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 279                   const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 280                   bool log_ecn_error);
 281 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 282                          struct ip_tunnel_parm *p, __u32 fwmark);
 283 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 284                       struct ip_tunnel_parm *p, __u32 fwmark);
 285 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 286
 287 struct ip_tunnel_encap_ops {
 288         size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 289         int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 290                             u8 *protocol, struct flowi4 *fl4);
 291 };
 292
 293 #define MAX_IPTUN_ENCAP_OPS 8
 294
 295 extern const struct ip_tunnel_encap_ops __rcu *
 296                 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 297
 298 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 299                             unsigned int num);
 300 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 301                             unsigned int num);
 302
 303 int ip_tunnel_encap_setup(struct ip_tunnel *t,
 304                           struct ip_tunnel_encap *ipencap);
 305
 306 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
 307 {
 308         const struct ip_tunnel_encap_ops *ops;
 309         int hlen = -EINVAL;
 310
 311         if (e->type == TUNNEL_ENCAP_NONE)
 312                 return 0;
 313
 314         if (e->type >= MAX_IPTUN_ENCAP_OPS)
 315                 return -EINVAL;
 316
 317         rcu_read_lock();
 318         ops = rcu_dereference(iptun_encaps[e->type]);
 319         if (likely(ops && ops->encap_hlen))
 320                 hlen = ops->encap_hlen(e);
 321         rcu_read_unlock();
 322
 323         return hlen;
 324 }
 325
 326 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 327                                   u8 *protocol, struct flowi4 *fl4)
 328 {
 329         const struct ip_tunnel_encap_ops *ops;
 330         int ret = -EINVAL;
 331
 332         if (t->encap.type == TUNNEL_ENCAP_NONE)
 333                 return 0;
 334
 335         if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
 336                 return -EINVAL;
 337
 338         rcu_read_lock();
 339         ops = rcu_dereference(iptun_encaps[t->encap.type]);
 340         if (likely(ops && ops->build_header))
 341                 ret = ops->build_header(skb, &t->encap, protocol, fl4);
 342         rcu_read_unlock();
 343
 344         return ret;
 345 }
 346
 347 /* Extract dsfield from inner protocol */
 348 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 349                                        const struct sk_buff *skb)
 350 {
 351         if (skb->protocol == htons(ETH_P_IP))
 352                 return iph->tos;
 353         else if (skb->protocol == htons(ETH_P_IPV6))
 354                 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 355         else
 356                 return 0;
 357 }
 358
 359 /* Propogate ECN bits out */
 360 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 361                                      const struct sk_buff *skb)
 362 {
 363         u8 inner = ip_tunnel_get_dsfield(iph, skb);
 364
 365         return INET_ECN_encapsulate(tos, inner);
 366 }
 367
 368 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 369                            __be16 inner_proto, bool raw_proto, bool xnet);
 370
 371 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 372                                        __be16 inner_proto, bool xnet)
 373 {
 374         return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
 375 }
 376
 377 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 378                    __be32 src, __be32 dst, u8 proto,
 379                    u8 tos, u8 ttl, __be16 df, bool xnet);
 380 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 381                                              gfp_t flags);
 382
 383 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 384
 385 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 386 {
 387         if (skb_is_gso(skb)) {
 388                 int err;
 389
 390                 err = skb_unclone(skb, GFP_ATOMIC);
 391                 if (unlikely(err))
 392                         return err;
 393                 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 394                                                NETIF_F_GSO_SHIFT);
 395         }
 396
 397         skb->encapsulation = 0;
 398         return 0;
 399 }
 400
 401 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 402 {
 403         if (pkt_len > 0) {
 404                 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 405
 406                 u64_stats_update_begin(&tstats->syncp);
 407                 tstats->tx_bytes += pkt_len;
 408                 tstats->tx_packets++;
 409                 u64_stats_update_end(&tstats->syncp);
 410                 put_cpu_ptr(tstats);
 411         } else {
 412                 struct net_device_stats *err_stats = &dev->stats;
 413
 414                 if (pkt_len < 0) {
 415                         err_stats->tx_errors++;
 416                         err_stats->tx_aborted_errors++;
 417                 } else {
 418                         err_stats->tx_dropped++;
 419                 }
 420         }
 421 }
 422
 423 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 424 {
 425         return info + 1;
 426 }
 427
 428 static inline void ip_tunnel_info_opts_get(void *to,
 429                                            const struct ip_tunnel_info *info)
 430 {
 431         memcpy(to, info + 1, info->options_len);
 432 }
 433
 434 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 435                                            const void *from, int len)
 436 {
 437         memcpy(ip_tunnel_info_opts(info), from, len);
 438         info->options_len = len;
 439 }
 440
 441 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 442 {
 443         return (struct ip_tunnel_info *)lwtstate->data;
 444 }
 445
 446 extern struct static_key ip_tunnel_metadata_cnt;
 447
 448 /* Returns > 0 if metadata should be collected */
 449 static inline int ip_tunnel_collect_metadata(void)
 450 {
 451         return static_key_false(&ip_tunnel_metadata_cnt);
 452 }
 453
 454 void __init ip_tunnel_core_init(void);
 455
 456 void ip_tunnel_need_metadata(void);
 457 void ip_tunnel_unneed_metadata(void);
 458
 459 #else /* CONFIG_INET */
 460
 461 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 462 {
 463         return NULL;
 464 }
 465
 466 static inline void ip_tunnel_need_metadata(void)
 467 {
 468 }
 469
 470 static inline void ip_tunnel_unneed_metadata(void)
 471 {
 472 }
 473
 474 static inline void ip_tunnel_info_opts_get(void *to,
 475                                            const struct ip_tunnel_info *info)
 476 {
 477 }
 478
 479 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 480                                            const void *from, int len)
 481 {
 482         info->options_len = 0;
 483 }
 484
 485 #endif /* CONFIG_INET */
 486
 487 #endif /* __NET_IP_TUNNELS_H */